#include<stdio.h>
int main()
{
    int a,i,b, n;
    printf("Thern are foolowing friendly - numbers pair samller than 3000:\n");
    for (a=1;a<3000;a++)
    {
        for (b=0,i=1;i<a/2;i++)
        if(!(a%i))b+=i;
        for (n=0,i=1;i<=b/2;i++)
        if(!(b%i))n+=i;
        if(n==a&&a<b)
        printf( " %4d..%4d",a,b);

    }
}